BL 6-inch Mk VII naval gun
|used_by= |wars=World War I World War II |prod_date= |type=Naval gun Coastal defence gun Heavy field gun |date= |designer=Vickers |design_date=1899 |manufacturer= |service=1901–72 (Fort Scratchley) 1915–18 (field use) |caliber= |part_length= (45 cal) |carriage= |breech= Welin interrupted screw |rate=8 rpm8 rounds per minute is the figure given by Vickers. Quoted in Brassey's Naval Annual 1901 |velocity= (light charge) (heavy charge)2,525 ft/s firing a projectile using Cordite MD size-16 propellant; 2,775 ft/s using Cordite MD size 26 was the standard naval loading in WWI. Twin mounts and unstrengthened P IV mounts were restricted to the light charge (Treatise on Ammunition 1915). The original loading was of the more powerful cordite Mk I size 20, but Mk I caused greater wear |cartridge=Lyddite, HE, Shrapnel Shell weights given are filled and fuzed i.e. as fired. was standard shell weight in WWI. Some earlier shells had slightly higher weights e.g. Mk IV common lyddite shell weighed |ammo_wt= |max_range=Field carriage Mk. II : Clarke page 23 quotes on the Mk II carriage; General Farndale page 130 quotes – this is possibly on the Mk I carriage. Naval : (light charge); (heavy charge)Tony DiGiulian, British 6"/45 (15.2 cm) BL Mark VIIAll figures for shell, which was standard in WWI. |recoil= |weight= (gun & breech) 25 tons (gun on field carriage) |length= |crew= |number=898 |variants= Mk VII, Mk VIII, Mk XXIV |filling_weight=Lyddite : Amatol : Shrapnel : 874 balls @ 27/lbFigures for WWI field gun. Hogg & Thurston 1972, Page 243 }} The BL 6 inch Gun Mark VII (and the related Mk VIII)Mk VII = Mark 7, Mk VIII = Mark 8. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. Mark VIII's breech opened to the left and Mark VII's opened to the right, allowing for paired mounts. Guns mounted singly were all the right-opening Mark VII was a British naval gun dating from 1899, which was mounted on a heavy traveling carriage in 1915 for British Army service to become one of the main heavy field guns in the First World War, and also served as one of the main coast defence guns throughout the British Empire until the 1950s. Background The gun superseded the QF 6-inch gun of the 1890s, a period during which the Royal Navy had evaluated QF technology (i.e. loading propellant charges in brass cartridge cases) for all classes of guns up to 6 inch to increase rates of fire. BL Mk VII returned to loading charges in silk bags after it was determined that with new single-action breech mechanisms a 6-inch BL gun could be loaded, vent tube inserted and fired as quickly as a QF 6 inch gun. Cordite charges in silk bags stored for a BL gun were also considered to represent a considerable saving in weight and magazine space compared to the bulky brass QF cartridge cases.Treatise on Ammunition 10th Edition 1915, page 393 Naval gun ]] The gun was introduced on the s of 1898 (commissioned September 1901) and went on to equip many capital ships, cruisers, monitors, and smaller ships such as the which served throughout World War II. Mk VIII in Naval service was identical to Mk VII, except that the breech opened to the left instead of to the right, for use as the left gun in twin turrets. Guns were mounted in the following ships : * s laid down 1898 * s laid down 1898 * s laid down 1899 * s laid down 1899 * s laid down 1899 * s laid down in 1901 * s , , , , laid down 1902 * cruisers laid down 1902 * , battlecruiser laid down 1912 * s as re-gunned in 1902 * s laid down 1912 * s as re-gunned in 1914 with guns from * of 1915 * s of 1915 In World War II the gun was used to arm British troop ships and Armed Merchant Cruisers, including , which briefly fought the German 11-inch gun battlecruisers and in November 1939, and which similarly sacrificed herself to save her convoy from the 11-inch cruiser in November 1940 . World War I field gun * They were first sent to France in 1915 mounted on improvised rectangular-frame field carriages designed by Admiral Percy Scott, based on the design he had improvised for 4.7-inch guns in the Second Boer War, and were successful.Hogg & Thurston 1972, Page 144 However, elevation and hence range was limited with the Scott carriages so a proper carriage, MK II, was introduced early in 1916, allowing elevation to 22°. Carriages Mks III, V and VI also appeared. , cutting wire for the Australian advance Second Battle of Bullecourt 21 April 1917]] It was operated by the Royal Garrison Artillery, as were all the larger guns, in World War I, in batteries of 4 guns. Following its successful employment in the Battle of the Somme its role was defined as counter-battery fire and also they "were most effective for neutralising defences and for wire cutting with fuze 106 new fuze which reliably burst instantly above ground on even slight contact, instead of forming craters", also for long-range fire against "targets in depth".Farndale 1986 page 158, quoting War Office Artillery Notes No. 4 – Artillery in Offensive Operations, January 1917. It was superseded by the lighter and longer-range BL 6-inch Gun Mk XIX which was introduced from October 1916 but the Mk VII remained in service to the end of World War I. Coast defence gun * on Ireland Island, Bermuda, with two BL 6-inch Mk VII.]] in 1943.]] , at St. David's Battery, Bermuda, in 2011]] ]] The 6-inch Mk VII gun, together with the 9.2-inch Mk X gun, provided the main coast defence throughout the British Empire, from the early 1900s until the abolition of coast artillery in the 1950s. Many guns were specially built for army coast defence use, and following the decommissioning of many obsolete cruisers and battleships after World War I, their 6-inch Mk VII guns were also recycled for coast defence. 103Farndale 1988, Page 404 of these guns were in service in World War I in coastal defences around the UK. Some of these, together with others at ports around the wider British Empire, played an important defence role in World War II and remained in service until the 1950s. A number of new similar guns with stronger barrels which allowed more powerful cordite charges to be used were manufactured for coast defence during World War II, and were designated 6-inch BL Mark XXIV.DiGiulian Notable actions In the German raid on Scarborough, Hartlepool and Whitby on 16 December 1914, a notable action was fought by Durham Company RGA of the Territorial Force at Heugh (2 guns) and Lighthouse (1 gun) batteries defending Hartlepool. They duelled with the German battlecruisers and (11 inch guns) and (8.2 inch), firing 112 rounds and scoring 7 hits. The battlecruisers fired a total of 1,150 rounds at the town and the batteries causing 112 civilians and 7 military killed.Farndale 1988, Pages 368–369, 401. World War I Ammunition See also * List of field guns * List of naval guns Surviving examples * At the Royal Artillery Museum Woolwich, London. * A coast defence gun at Newhaven Fort, Sussex, UK * A gun mounted on the 1904 coast defence emplacement at New Tavern Fort, Gravesend, UK * 2 coast defence Mk 7 guns at Fort Dunree, Lough Swilly, in County Donegal, Ireland * St. David's Battery, St. David's Head, St. David's Island, Bermuda. Two Mk VII RBLs, built by Vickers, on Central Pivot Mk II mounts. * Fort St. Catherine's, St. George's Island, Bermuda 6-inch BL Gun Mk VII Gun, built by Vickers, on Central Pivot Mk II mount. * Warwick Camp, Warwick, Bermuda. Two Mk. VII, built by Vickers, on Central Pivot Mk II mounts. (This is an active military base, and the battery is not accessible by the public. The barrels have reportedly been removed, recently, for remounting on the bastions of the Keep, at the Royal Naval Dockyard, on Ireland Island, which houses the Bermuda Maritime Museum. * Royal Naval Dockyard, Ireland Island, Bermuda. Two Mk VII (L/1029 and RGF) on Central Pivot Mk II, at Bastions C and D of the Keep (fortress) which houses the Bermuda Maritime Museum (there is also one BL 6-inch Gun Mk II and one BL 6-inch gun Mk IV, at Bastion E).The Bermuda Maritime Museum; Guns and DefencesSurviving American Seacoast Artillery Weapons. Compiled: Lists in CDSG News/Journal prepared by C.L. Kimbell (1985), R.D. Zink (1989), and T.C. McGovern (1992 and 1996) (Google document reader) * A gun on field carriage at The Front Museum, Lappohja, Finland * Fort Ogilvie, Point Pleasant Park, Halifax, Nova Scotia * VSM gun No. 1553 dated 1901 at Princess Royal Fortress, Albany, Western Australia. Obtained from Bermuda during restoration of the site in the 1980s. * Barrel 1489 which fired the first Australian shot of WWI, and 1317 which fired the first Australian shot of WWII at Fort Nepean, Victoria * Mk VII gun dated 1902 at Ile aux Aigrettes, Mauritus * http://www.southpacificphotography.com/photos.cfm/PhotoId/316/momi-gun-coral-coast.html Momi, Vuda, Batteries, Viti Levu, Fiji Islands. One of the barrels is #1266 from 1900 * Fort Mitchell, Spike Island, Ireland, 2 Mk VII Guns in casemates on Central Pivot Mk II mounts in good condition and in the process of being restored to full working condition. Notes and references Bibliography * * Dale Clarke, British Artillery 1914–1919. Heavy Artillery. Osprey Publishing, Oxford UK, 2005 ISBN 978-1-84176-788-8 * Tony DiGiulian, British 6"/45 (15.2 cm) BL Mark VII 6"/45 (15.2 cm) BL Mark VIII 6"/45 (15.2 cm) BL Mark XXIV * General Sir Martin Farndale, History of the Royal Regiment of Artillery. Western Front 1914–18. London: Royal Artillery Institution, 1986. ISBN 978-1-870114-00-4 * General Sir Martin Farndale, History of the Royal Regiment of Artillery. The Forgotten Fronts and the Home Base, 1914–18. London: Royal Artillery Institution, 1988. ISBN 978-1-870114-05-9 * I.V.Hogg & L.F. Thurston, British Artillery Weapons & Ammunition 1914–1918. London: Ian Allan, 1972. ISBN 978-0-7110-0381-1 * Admiral Percy Scott, "Fifty Years in the Royal Navy" published 1919 External links * Ken Musgrave, Diagram of BL 6inch Mk VII Gun on Mk. 2 Carriage at Landships (scroll to bottom of page) * Per Finsted, Om den engelske 6-tommers feltkanon 1914–1940 (in Danish) Category:World War I artillery of the United Kingdom Category:World War I guns Category:Naval guns of the United Kingdom Category:World War I naval weapons of the United Kingdom Category:152 mm artillery Category:Vickers Category:Coastal artillery